Inductor crisis averted! For 4/6 ohm builds, I'm using 10uH Sagami 7G14D-100M. This inductor is getting bought/shipped separately and costs more than the ICE Components part, so pricing has been increased for configurations that use 10uH inductors. Here's the current price list:

Not many days left to get your orders in. I'm stopping the group buy as soon as the PCBs ship from elecrow, and making my Mouser/Digikey orders.

== UPDATE - FEB 17 ==

Group buy is on! I'll be accepting payments for ~3 weeks, or however long it takes me to get a prototype ordered/built/tested/verified. Once that's done, I'll close the door on payments and order PCBs/parts.

My paypal address is (posted as an image for spam reasons):
[REMOVED - group buy now closed]

Remember to pay in $CAD - if you pay in $USD you're overpaying.
If you're ordering a fully built amplifier, make sure to specify the load impedance (4 ohm, 6 ohm/TI, 8 ohm, 16 ohm)
If you're ordering a PCB + microcontroller, make sure to specify separate-in-a-bag or soldered on - price is the same either way.

One day I was stuck home in a snowstorm, and decided to bang out a card design that met his requirements. Soon several other people started throwing in suggestions and requests, and the design evolved into something we all feel pretty good about. AudioLapDance himself proclamed "we have a wiener!", and the name stuck.

Here it is:

Top PCB:

Bottom PCB:

Schematic:

== Features ==

- Small size (5x10cm)
- TPA3118 amplifier IC (more on this choice below)
- Everything is easily and quickly configurable - AMx and MODE pin settings, gain setting and master/slave mode can all be set with DIP switches, and a trimmer pot is provided to allow PLIMIT voltage adjustment.
- 2 stereo channels. The card is configurable into PBTL mode if you want, though unlike DUG's card it's primarily intended to be a stereo design.
- "Wideband" PVCC decoupling, using multiple capacitors chosen to provide a low PVCC impedance from "audio to VHF"
- Additional decoupling on the AVCC pin
- Snubbers before and after the output filter.
- Good quality output filter (ICE Components 1D14A, Epcos 32529J film)
`--> Multiple filter options available for purchase: 4 ohm (10uH/1.5uF), 6 ohm (10uH/0.68uF, standard TI configuration), 8 ohm (15uH/0.47uF) and 16 ohm (33uH/0.22uF)
- Good quality film input caps (2.2uF EPCOS film), footprint will also accept 1210 ceramic capacitors and through-hole bipolar electrolytic capacitors.
- Microcontroller-controlled power up sequencing, with an adjustable startup delay to mitigate turn-on pops with unbalanced sources or large input coupling caps.
- Connections provided for a standby switch and a power LED.
- Good ESD protection on all inputs.

== So, uh, why the TPA3118? ==

To make room for decoupling caps.

The TPA3118 is actually the exact same IC as the TPA3116, but with a bottom side thermal pad for PCB heatsinking. Provided you can sufficiently heatsink the TPA3118, it's capable of the same output power and audio performance as the TPA3116.

In this design, the PCB has lots of thermal vias and an unbroken ground plane under the TPA3118, providing a lower thermal resistance than the heatsinks you find on most of the TPA3116 cards out there. By bolting the card to a metal enclosure and putting a thermal pad between the PCB and the chassis cooling can be even further improved.

With no top side heatsink to interfere with them, decoupling capacitors can be brought very close to the TPA3118 pins for improved performance. Achieving the same electrical performance with a TPA3116 would require the heatsink to be machined to provide clearance for the close-in decoupling, or a small heatsink barely larger than the TPA3116 itself which would not be as thermally effective as the PCB here.

== Cost ==

For bare boards:
- Bare PCB: $8.00
- Add programmed microcontroller, either in a static bag or soldered to PCB - additional $2
- Add a soldered on and tested TPA3118: additional $15.
- Shipping is $8 to the US and $10.50 international for up to 4 PCBs, using Canada Post "Light Packet" service. Within Canada, use the Canada Post shipping calculator for a 6x9x0.5" parcel that weighs 1/4lb, shipped from postal code B3Z 1R3, add $3 to whatever it spits out, and PM me to verify.

For shipping elsewhere or using a different shipping method, hop on Canada Post - Mailing, Shipping, Marketing, Shopping, Sharing click "find a rate" and calculate the shipping cost for a 6x4x3 inch box, weight 1lb, from postal code B3Z1R3 to wherever you are, then add $3 for packing supplies and PM me to verify.